突水作用下深埋公路隧道衬砌受力特征及安全性分析

Mechanics Characteristic and Safety Analysis of Lining of Deep-buried Highway Tunnel under Water Inrush

突水是造成隧道运营期二次衬砌开裂渗水的原因之一。为分析突水作用对二次衬砌的内力及安全性影响,依托某深埋公路隧道,采用ANSYS软件建立二维数值模型,分析了不同突水位置、水压力大小下公路隧道衬砌的受力特征及安全性。研究结果表明:衬砌局部突水的压力、位置对衬砌内力影响显著;衬砌突水压力作用位置在仰拱时,衬砌受力最不利,其安全系数明显小于其他部位;突水对衬砌的内力有叠加(或抵消)的现象,在设计时应予以考虑。

Water inrush is one of the reasons for cracking and seepage of secondary lining during tunnel operation.In order to analyze the impact of water inrush on the internal force and safety of secondary lining, a deep-buried highway tunnel is relied on. A two-dimensional numerical model is established by using ANSYS software, and the stress characteristics and safety of highway tunnel lining under different water inrush positions and water pressure are analyzed. The results show that the pressure and position of local water inrush of lining have significant influence on the internal force of lining. When water inrush pressure of lining is applied to the inverted arch, the lining is under the most unfavorable stress, and its safety factor is significantly lower than that of other parts. The internal force of lining is superimposed(or offset) by water inrush, which should be considered in design.